I don't know that the symbolism is to be found in the Narghiles
themselves, but rather in the events going on around them.

If you take a moment to consider, it appears that the Narghiles are
secondary to the drugs they carry. Why does Rorty want to destroy
them? Not because of the species as a whole, but because of the
drug it produces.

In furtherance of the idea that the Narghiles are not the intended
focus of symbolism, take 'Brave New World' for instance (bet
Trevor's read that a time or two)...is the book's message and
symbolism found in the drug Soma, or in the politics and sociology
of the book's characters?

Soma is something the government uses to help them control the
masses, so really it's just a vehicle to the story.

The same may be said for "Reraizure", I think; a drug is a drug. I
suspect it could've been anything...the Narghiles, living creatures
producing the drug, just happened to be an interesting idea.

However, I won't claim to know any of this for sure. I ain't Peter,
just a chick who has too much time to watch TV. ;)